The Odiel is a river in the Atlantic basin in southern Spain, more precisely in the province of Huelva, Andalusia. It originates at Marimateos in the Sierra de Aracena at an elevation of above sea level. At the Punta del Sebo, it joins the Rio Tinto to form the Huelva Estuary. Its principal tributaries are the Escalada, Meca, Olivargas, Oraque, Santa Eulalia, and El Villar. Its basin covers .